So I noticed that glitching, especially between the stones, could become a problem. Even if I have not found any glitches that give advantage, I would recommend to add temporary squares that shows the unpassable area in the game during the tests. I know Game Jams give a very short time for fixing minor things like glitches and I do not even know if the mechanics allow those squares for debugging but I think they could help.
Just a tip if you want to create a similar game in the future or want to continue this project. :)